Coren was born in Essex, England. He moved from the UK to Canada in 1987. For several years, he was a columnist for Frank and then The Globe and Mail, before he began syndicated columns for the Financial Post and Sun Media in 1995. Following his departure from Frank, he became a favourite target of that publication, culminating in a spoof ad contest to "deflower" Michael Coren (a nod to Frank's notorious "Deflower Caroline Mulroney" contest, and a satirical jab at Coren's conservative leanings.) Coren had also been a favorite target of Frank back in the days before he began writing for them. Coren took exception to being labelled a "literary prostitute" during a 1994 interview.

His career as a broadcaster began in the early 1990s when he co-hosted a political debate segment with Irshad Manji on TVOntario's Studio 2. In 1995, he began an evening talk show on CFRB. In 1999, Coren briefly moved to Talk 640 for a short stint as its morning man. He returned to CFRB, where he hosted a show from 6:30 to 8:00 p.m. weekday nights, and regularly filled in for other hosts until November 2005. Coren was dismissed by CFRB as a result of complaints arising fromcomments ridiculing the weight of an apparent guest. In fact, the guest was an actor and the segment was scripted. According to CFRB's Operations Manager, Steve Kowch, "Pat Holiday, our general manager and myself went through the tape of Monday night's show and were shocked....it was totally out of bounds." Coren argues that it was a satire comparing in his mind public attitude to third world starvation with North America's obsession with slimming and self-indulgence. After moving to North America Coren gained one hundred pounds.

Despite this acrimonious termination, Coren made regular talk show appearances on CFRB in July 2006, at the start of the 2006 Israel-Lebanon conflict, as he happened to be in Israel at the time. After receiving 60% approval from CFRB listeners in an August 2006 poll, Coren returned to the CFRB airwaves in September 2006 with a Sunday evening show. As of the 22nd of April 2007, the show expanded from its usual 1 hour 7-8pm to 7-9 pm. Coren celebrated by giving away double the prizes usually given out. In the fall of 2007 he and former Liberal Party of Canada president Stephen LeDrew launched a daily hour-long afternoon show on CFRB called Two Bald Guys With Strong Opinions in which the two argue about the issues of the day. After the departure of LeDrew, Coren was joined by Tarek Fatah after several on air auditions by potential replacement co-hosts. Coren was again let go by CFRB along with 12 other staff of the Toronto radio station on 27 August 2009.

On television, Coren hosts The Michael Coren Show weeknights on Crossroads Television Services, and is published every Saturday in the Sun newspaper chain. He is also a columnist for the Western Standard, Catholic Insight and The Women's Post and writes regularly for the National Post, Reader's Digest and several other publications. A self-professed Tottenham Hotspur fan, he has appeared as a guest host on The Score's The Footy Show. Coren is also a public speaker, particularly at religious gatherings.

In his earlier, satirical Aesthete column in Frank magazine Coren was by his own admission deliberately provocative. In response to a 1994 interview question about AIDS he responded:

"Look, people are dying all over. When it was blacks in Africa dying of AIDS, no one gave a toss. Nobody gave a toss. Suddenly, it's middleclass men in California and everyone goes crazy about it. It's a double standard. I'm trying to provoke people into rethinking comfortable points of view."

In September 2006, Coren published an article in the Toronto Sun, supporting the use of tactical nuclear strikes against Iran. TorontoSun.com - Michael Coren - We should nuke Iran This position was later retracted. TorontoSun.com - Michael Coren - How wrong can I be?

On the subject of AIDS Michael Coren has said that "While everything human must be done to find a cure for this plague, it is hard to deny that the majority of sufferers in North America contracted the disease through perverse sex. 95% of the world's AIDS population is in the developing world and lack even basic health care. Nobody cared very much about these men and women before AIDS was brought to North America and, frankly, nobody cares very much now." In keeping with this theme he wrote a column in 2006 titled "Why is AIDS so special?" in which he said "At its most simple, stop fornicating." "AIDS in the West is still overwhelmingly a threat to male homosexuals and intravenous drug users."

Coren wrote "According to the standard histories of the Holocaust, some eight percent of those killed in the camps were of the sodomite persuasion... Yet there may be a more opposite and fitting symbol of tribal identity for these poor oppressed people. If we are to believe the Cambridge History of the Second World War, and Gerber's surely definitive The Evolution and Structure of the Nazi Party, over twenty percent of the membership of the German National Socialists were practising pederasts...Surely our homosexualist brothers and sisters would be advised to abandon the pink triangle and opt for a tiny but telling swastika lapel pin instead." The gay Nazi claim has been disputed on a number of occasions.Moser, Bob. "Making Myths", "Southern Poverty Law Center", Montgomery, AL, Spring 2005. In an article which appeared in the Sun on May 22, 2007, Debate over sexual orientation dividing Christians, Michael Coren said "As for Jesus not condemning homosexuality, nor did He condemn bestiality and necrophilia."

His articles and speeches often include stories of his own personal spiritual journey. Coren's father was Jewish as was his maternal grandfather, while his maternal grandmother came from a family of Welsh coalminers and converted to Judaism. Coren's father and uncle were cab drivers. Coren has said that his father's family left Poland a few decades before the Holocaust. He has also said that his father's family emigrated from Poland in the 1890s. He said "People have called me an anti-Semite. I thought it quite rich since my father's family was massacred in the Holocaust". Michael Coren was profiled on Credo, on Vision TV, and said that his father told him he could not attend his son's wedding in a Catholic Church without becoming "physically sick."

He converted to Roman Catholicism in his early twenties while still living in England, but that didn't last long. He said that he "converted to an institution." He eventually converted to Evangelical Christianity in the 1990s, after a conversion experience as an adult, greatly influenced by Canadian televangelist Terry Winter.

In 1991 Michael Coren said in a column for a humour magazine "The evangelical Christians may be intolerant, small-minded, and repellent, but at least they hold a consistent set of beliefs".

In a 1993 book review he said "Can anyone imagine a detective priest? Regrettably, it is easier to conjure up the image of a priest being questioned by secular detectives over abuse charges." Also in 1993, Michael Coren had a falling out with the Catholic Church over an unflattering profile he wrote of Archbishop Aloysius Ambrozic for Toronto Life magazine. The Bishop, who made Coren a "Knight of the Holy Sepulchre" in a ceremony in October 1992, was quoted using words including "friggin" and "bitch", and said that Francisco Franco was a "conservative Roman Catholic and not a bad fellow." Coren defended himself, saying "He's an archbishop and he was vulgar...obviously what thousands of Roman Catholics expected me to do was lie. I still get hate mail about the article."

After this incident, Coren said that he didn't consider himself a Roman Catholic anymore. He said "My wife is Catholic and the children will be raised Catholic, but that's it. It's just not there for me." Daniel Richler observed that Coren loves scandal, but hates having it come his way. In one of his columns for the satirical humour magazine Frank, Michael Coren depicted Mother Teresa getting drunk in a bar.

In early 2004, he embraced Catholicism again. He cites St. Thomas More, C. S. Lewis, Ronald Knox and his godfather Lord Longford as spiritual influences, and remains connected to the ecumenical scene in Canada and beyond.